Sound-recording and sound-reproducing instrument



Fig-.5. I

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F. KAY ET AL SOUND RECORDING AND SUND REPRODUCING INSTRUMENT Filed May 24, 1924 naar @een Patented Apr. 27., 1926.

UNITED STATES PATENT OFFICE.

FRED KAY, OF IPECKHAM, LONDON, vAND WILLTAM ERNEST CLIFTON, OF LONDON, ENGLAND, ASSIGNORS '.I'Ov CLIFTOPHONE LIMITED. 0]!" LONDON, ENGLAND, A

BRITISH COMPANY.

SO'UND-RIECORIJINGA AN D SOUND-REPRODUCING INSTRUMENT.

Application filed May 5:24, 1924. Serial No. 715,605.

To all whom, t may concern:

Be it known that We, FRED KAY, a subject of the King of England, residing at Peckham, London, England, and VILLTAM ERNEST CiJrToN, a subject of the King of England, residing at London, England, have invented new and useful Improvements in Sound-Recording and Sound-Reproducing Instruments, of which the f ollowingis a specification.

This invent-ion consists in improvements in or relating to sound-recording and soundreproducing instruments and has for its object to provide an improved construction of diaphragm for use in such instruments and improved means for attaching the stylus-bar connector thereto.

Sound-recording or sound-reproducing instruments of the type contemplated by the present invention, are well-known, for example in their use with gramophones and like machines. Such instruments consist broadly in a vibratory diaphragm held within a casing, and an oscillatory stylusbar mounted with one end connected to the diaphragm and the other end formed with or constructed to receive al stylus or needle.

One feature of the present invention coinprises the combination of a diaphragm-element having a pocket formed therein or thereon, a metal disc orpart which is completely or substantially completely enclosed in said pocket, and a pin' secured to or integral with said metal disc or part so as to extend outwardly from the surfaceof the diaphragm, with or without cementing material of the kind hereinafter referred to applied between tlie metal disc or part and adjacent surfaces of the pocket.

According to another feature of the invention, the metal disc or part is applied to a main diaphragm-element so as to overlie a part of the surface thereof, and means are employed to effect adherence between the metal disc or part and the diaphragm or an intermediate element disposed between the metal disc or part and the diaphragm. In such a construction there is preferably a Celluloid. or other cover overlying the metal disc or part and4 secured at its inargins to the main diaphragm-element so as to enclose the said disc or part between it and the diaphragm. In a preferred form the cover is so applied that its-'edges -merge smoothly into the surface of the main dia- .phra'gm-element.,l 7

Preferably there is a Celluloid or other cover overlying the said disc oi metal part and secured at its margin to the main diaphragm-element so as to enclose the metal disc or part between it and the diaphragm.

The foregoing and other features of thev inventibn will be more .clearly undeistood from the following description of some preferred constructions, given by way of cxample only, wit-h the aid of the accompanying drawings, in which Figure 1 a plan of one form ofl diaphragm ,according to the invention;

Figure 2 is a section on the line 2-2' of Figure 1; i

Figure 3 is a section similar to Figure 2 on an enlarged scale through the, centre part only of the diaphragm;

Figures 4, 5 and 6 are again similar sections of modified constructions according to the invention;

Figure7 is a still further modification o the invention; and

Figure 8 illustrates a modified detail of the invention.

Like reference numerals ,indicate like parts in the lseveral figures of the drawings. Referring to Figures 1-3, a. disc 10 constituting the main diaphragm-element, is preferably composed of celluloid of, say, tento fifteen-thousandths ofan inch in thickness.' As. will be seen more clearly from Figure 3, a stifiening-element l1, in the form of a disc (for example thin paper of approximately seven-thousandths of an inch in thickness) is positioned centrally in the disc 10. A short'pin 12 passes centrally through the sti'eningelement 11, and terminates in a small metaldisc 13 with which it is integrally foimed or to which it is rigidly secured, for example by soldering or welding.. Between the disc 13 and the stienin g-'element 11 a thin disc of Celluloid.

layers cementing/material may be employed and conveniently the surfaces of the Celluloid ,pressing operation parts, that is to say the diaphragm 10, celluloid disc 14 andcover-plate 15, are moistened with a celluloid solvent such as methyl-acetate so as to render those surfaces adhesive prior to the heating and pressing operation. rFhus, the cementing material may be constituted by the moistened and partially dissolved surface of the Celluloid parts and wherever reference is made herein to a cementing material it is` .on the other side of thel metal disc and located between it and the diaphragm disc 10. A further celluloid disc 17 is interposed between the metal disc 13 and the second stiening-element 16.

Alternatively, as shown in Figure 5, the second stifening element 16 may be applied to the disc 15 on the opposite side to that on which the element 11 lies.

A s an alternative construction, the stiifening element may be omitted as shown in Figure ti. ln this figure the central portion of the diaphragm-disc is formed at 18 with a somewhat dome-like cavity and the metal dise 13 is shaped so as closely to overlie the dome sofornied. The Celluloid cover-plate 15 is pressed tightly over the metal disc 13 so as complet/ely to enclose the metal disc between it and the portion 18 of the diaphragm. This form of diaphragm per se does not constitute part of thefpresent invention but comprises the subject-matter of co-pending application in Great Britain No. 31421/23.

lin order to permit a more ready yielding of the diaphragm, it may be formed as shown in Figures 1 and 2, with a circular corrugation 19 closely surrounding the central portion to which the disc 13 is applied. 'llhis corrugation 19 isL shown also clearly in Figures 4, 5 and G. rl"here may be a second concentric corrugation 20 spaced from the first and disposed between the first and the outer margin of the diaphragm. Between the two circular corrugations additional (radial) corrugations such as 21 may be formed but 'it is to be understood that the particular form of the corrugation may be varied or may, if necessary, be omitted entirely. ln all the constructions illustrated, some or all of the corrugations 19, 2O and 21 may be provided as found most desirable.

-sueh as are described above.

atea/ive llt is obvious that with the construction shown in Figures 1-5 the stiffening-elements such as 11, 16, 17 may be omitted if preferred, as shown for example in Figure 6where the disc 13 is shown as contained' directly between tthe main diaphragm-disc 10 and the cover-disc 15. lt is often found advantageous when a fiat central portion 'of the diaphragm is utilized, to employ one or morestiffening-elements lt will be realized, however, that an important feature of the present invention is the manner in which the pin 12 is secured to the diaphragm and this differs from all previously known constructions. Risk of the pin 12 working loose in its connection with the diaphragm is found to be, for all practical purposes, eliminated'by the present construction and the pin virtually constitutes an integral part of the diaphragm. Hitherto considerable diiiiculty has been experienced in maintaining pins such as 12 suflicient-ly tightly attached to the diaphragm. Riveting or the use of nuts screwing on to the end of the pin to clamp the latter to the diaphragm, scaling material applied to the head of the' pin to secure it tothe diaphragm, and many other means have previously been tried without the same degree of success as is obtained by means of the present invention.

ln place of the metal disc 13, illustrated in the foregoing examples as a flat plate to which the end of the pin is secured, the disc lo() may be formed by Jumping up a head on the end of the pin. Alternatively, as shown in Figure 8, thedisc may be constituted by spiralling one end of the pin 12, as at 22, 'the convolutions of the spiral being secured together, for' example by soldering if found necessary or desirable. 'F hey may, however,

4be left unconnected with the convolutions closely coiled one on the other.

.ln a further alternative the disc may be replaced by a straight strip of metal which is bent into V-section so that the pin extends in a direction which is normal to the groove of the V and is secured to the concave apex thereof.

From the foregoing description it will be seen that the Celluloid cover 15, considered in conjunction with the main diaphragmelement 10, constitutes a pocket within which is enclosed the metal part 13. 'lhe present invention, therefore.. contemplates and includes the formation of a pocket in the diaphragm into which the metal disc or part may be inserted, whereafter the pocket is closed down on to the metal disc so as to hold it tightly therein.

1. A diaphragm of the type described comprising in combination a' main diaphragm element, a metal part secured there.

disc or other l2 CII on, a pin projecting from said metal part,

Q. A diaphragm of the type described comprising in combination a main diaphragm element, a metal part securedthereon, a pin projecting from said metal part, and a cover which overlies said metal part,

which extends marginally beyond it andwhich is secured at its margin to the diaphragm element in such a manner that its edges merge smoothly into the surface of the diaphragm element and the metal part is enclosed'between, the cover and the diaphragm element. v

3. A diaphragm of the type described comprising in combination a. main diaphragm element, a metal part and a stiftening clement secured thereo; a pin projecting from said metal part, and a cover which overlies the metal part and the sti'tiening element, which extends marginally beyond them and which is secured at its margin to the diaphragm element so as to enclose the metal part and still'ening element between the cover and the diaphragm element.

4. A diaphragm of the type described comprising in combination a main diaphragm element, a metal part secured thereon, a still'ening element between the said metal part and the diaphragm element, a pin projecting from said met-.1l part, and a cover which overlies said metal part and stili'ening element, which extends marginally beyond them and which is secured at its margin to the diaphragm element so as to enclose the metal part and stiiiening element between the cover and the diaphragm element.

5. A diaphragm of the type described comprising in combination a main diaj'ihragm element, a metal part secured thereon, a still'ening clement on each side of said metal part so that one of them is between the latter and the diaph agin element, a pin projecting from saidinetal part, and a cover which overlies saidinetal part and stifi'cning elements, which extends 4marginally beyond them and which is secured at its margin to the diaphragm element so as to enclose the metal part and the stillcning elements between the cover and the diaphragmelement.

(S. ,A diaphragm of the type described comprising in combination a main diaphragm element, a metal part secured thereon. a pluralit \y oi stillcning elements with the mel-al part arranged between two of them. a pin projecting from said metal part, and a cover which over-lies said metal part and still'eningelements, which extends marginally beyond them and which is secured at its margin to the diaphragm element so as to enclose the metal part and the stili'ening elements between the cover and element. l i

7. A diaphragm of the type described comprising in combination a main diathe diaphragm lphragm element, a metal disc secured thereon so as to lie fiat over the surface of the diaphragm element, a pin projecting from said disc, and a cover which overlies the disc,

which extends marginally beyond it and which is secured at its margin to the diaphragm 'elementso as to enclose theI disc between the cover and the diaphragm element.

8. A diaphragm of the type described comprising in combination' a main diaphragm element, a metal'disc secured thereon so as to lie flat over the diaphragm element, a stiffeningdisc concentric with thev metal disc, a pin projecting fromfsaid metal disc, and a cover which overlies said metal and stiliening discsz which extends marginally beyond them and which is secured at its margin to the diaphragm element so as 'to enclose the discs between the cover and the diaphragm element. v j

A diaphragm of the type described-comprising in coilnbination la diaphragm .element, a metal part secured thereon, a pin projecting from said metalpart, and a cellnloid cover which overlies ,said metal part, which extends marginally beyond it and which is secured to the diaphragm element and to the metal part so as to connect said part lirmly between the cover andv the diaphragm element.

10. A diaphragm of the j type described comprising in combination a Celluloid diaphragm element, a metal part secured sof sis

thereon, a pin projecting from said metal part, and a celluloid cover which overlieS` said metal part and whichextends marginally beyond it, the diaphra element, metal disc and Celluloid cover bemg adhesively secured together so that the metal part is enclosed firmly between the cover and the diaphragm element.

l1. A diaphragm of the type described comprising in combination a Celluloid diaphragm element, a metal part secured therecomprising in combination a`celluloid diaphragm disc, a metal disc secured thereon so to lie Hat over the diaphragm disc, a pin projecting from said metal disc, a Celluloid cov'er disc which overlies said metal part and which extends marginally beyond it, and celluloid adhesive means for securing1 all the parts togethenin such a manner that the edge of the cover disc merges smoothly into the surface of the diaphragm disc.

13. A diaphragm of the type described comprising in combination a main diaphragm element, a metal disc secured thereon so as to lie flat over the diaphragm element, a pin projecting from said metal disc, and a cover which overlies said metaldisc, which extends marginally beyond vit and which is secured at its margin to the diaphragm element so as to enclose the metal disc between the cover and the diaphragm element, said diaphragm element .being formed with a circular corrugation concentric with said metal disc and closely surrounding it, for the purpose described.

14. A diaphragm of the type described comprising in combination a main diaphragm element,.a metal disc secured therelie Iiat over the diaphragn'i element, a piu projecting from said metal disc, and a cover which overlies said metal disc, Which extends marginally beyond it and which is secured at its margin to thel diaphragm element so as to enclose the metal disc between the cover and the dia )hravm i esame said diaphragm 'element being Jiormed with a circular corrugation concentrie with said metal disc and closely surrounding'it, and with a second concentric corrugation spaced 'from the first-named corrugation, for the purpose described. t

lo. A diaphragm of the'type described comprising in combination a main. diaphragm element, a. metal disc secured thereon so as to lie flat over the diaphragm element,I a pin projecting Jfrom said metal disc, and a coverivhich orerlies said metal disc, which extends marginallybeyond it and which is secured' at its margin to the diaphragm' element so as to enclose the metal disc between the cover and the diaphragm element, said diaphragm element being formed with a circular corrugation concentric with said metal disc. and closely surrounding it, with a second concentric corrugation spaced from the irst-nained corrugation, and with substantially radial corrugatious extending between the two circular corrugations, l'or the purpose described.

lin testimony whereof We have signed our naines to this specification.

` l41 RED KAY.

element, 

